Large FLT Temp files are created by the Windows Indexing Service. If you spent a lot of time connected to large network shares or have lots of small files on your computer then you may encounter problems. This is because the Indexing Service spends a lot of time creating indexes for all those files, this slows the computer down because the Indexing Service is constantly writing to the hard drive. The good news is that the Windows Indexing Service is not essential and if it’s slowing your computer down or its filling your hard drive up with large .FLT files you can disable it, this will fix the problem:
To disable the indexing service:
1. Click the “Start” menu, choose “Control Panel.”
2. Double Click on “Administrative tools”, then open “Services”
3. Find “Indexing Service” in the list, then double-click on it.
4. If it’s running stop it by clicking the “Stop” button.
5. To stop the service from running again change “Start-up Type:” to “Disabled.”